freelancer for firebase firestore apps full stack development react concurrent mode back end developer mern stack developer web design full stack web developer hire full stack developer dotnet developer web design company freelancer for biometric time tracking zustand react state library nextjs app development freelancer for openai integration react https://zanejnmrz.life3dblog.com/35206225/the-2-minute-rule-for-cheapest-software-developers-in-the-world